Can inrush currents in transformers be avioded

Many compromises and different Inrush current limiters, intended to solve problems due to INRUSH CURRENTS, have been available in the  past. New techniques can help avoid this unwanted phenomena but in many cases careful consideration of the transformer design and its usage are also helpful.

The necessary procedure for transformer soft start with a TSR (Transformer Switching Relay) to avoid Inrush current peaks is: First pre magnetizing and then to drive the device in the correct way to fully switch it on.

A unique technique with thyristor and electro-mechanical relay, controllable with an external contact or voltage, the TSR are short circuit proof when correctly fused. The Thyristor inside of the TSR can withstand effective currents in excess of than 500A  for up to 10 msec.

Emeko Ing. Büro M.Konstanzer,

D79114 Freiburg, Tel. 0049 761 441803

Emeko@t-online.de

www.emeko.de